Two Non-π-Conjugated Deep-UV Nonlinear Optical Sulfates

Yanqiang Li; Fei Liang; Sangen Zhao; Lina Li; Zhenyue Wu; Qingran Ding; Shuai Liu; Zheshuai Lin; Maochun Hong; Junhua Luo

doi:10.1021/jacs.9b00138

Two Non-π-Conjugated Deep-UV Nonlinear Optical Sulfates

J Am Chem Soc. 2019 Mar 6;141(9):3833-3837. doi: 10.1021/jacs.9b00138. Epub 2019 Feb 25.

Authors

Yanqiang Li^{1

2

3}, Fei Liang^{1

4

3}, Sangen Zhao¹, Lina Li¹, Zhenyue Wu^{1

3}, Qingran Ding^{1

3}, Shuai Liu¹, Zheshuai Lin^{4

3}, Maochun Hong¹, Junhua Luo¹

Affiliations

¹ State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences , Fuzhou , Fujian 350002 , China.
² School of Physical Science and Technology , ShanghaiTech University , Shanghai 201210 , China.
³ University of Chinese Academy of Sciences , Beijing 100049 , China.
⁴ Technical Institute of Physics and Chemistry, Chinese Academy of Sciences , Beijing 100190 , China.

PMID: 30791686
DOI: 10.1021/jacs.9b00138

Abstract

The non-π-conjugated sulfate system has long been overlooked as potential deep-UV nonlinear optical (NLO) materials. Here we report two asymmetric anhydrous sulfates, namely, NH₄NaLi₂(SO₄)₂ (Ι) and (NH₄)₂Na₃Li₉(SO₄)₇ (Π), which consist of non-π-conjugated [SO₄]^2- anions. Their single crystals can be readily grown by a facile evaporation method from water solution. Both sulfates are transparent down to the deep-UV region. Interestingly, there is a large NLO gap between I and Π, with phase-matching NLO responses of 1.1 and 0.5 times that of the benchmark KH₂PO₄, respectively. The first-principles studies reveal that the non-π-conjugated [SO₄]^2- anions are the dominate NLO-active groups, and the large NLO gap between I and Π can be ascribed to the nonbonding O 2 p orbitals of different orientations in the crystallographically independent S1O₄ groups. This work provides an innovative non-π-conjugated source that is distinct from the traditional π-conjugated ones for deep-UV NLO materials.